The invention concerns a device as well as a procedure for slitting open sacks, especially coffee sacks by means of rotating cutting members like blades or discs.
Devices and procedures of this kind are well known. With these devices and procedures, a transport unit of sacks, for instance coffee sacks, frequently the cargo of a transoceanic container, is unloaded on a chute or slide, which tapers conically or in funnel shape, in order to make possible an isolation of the unloaded sacks. Isolated in this way, the sacks are then carried by means of conveyor belts and similar conveyances to a device for slitting open the sacks. The device for this consists of a shaft equipped with blades or disks, which is mechanically driven and which slits open the sacks lengthwise. The pile, consisting in this example of coffee sacks and coffee beans, is conveyed to a separation machine, which separates out the slit-open coffee sacks in a manner well-known. The separated coffee sacks can then be disposed of or recycled in the usual ways.
This installation and its associated procedures are very costly and cannot be operated without attendant personnel. So, for example, it is unavoidable that at the funnel-formed end of the chute, an attendant must be posted, who with muscle-power removes the sacks that inevitably again and again become wedged together. It is also possible that, before the device for slitting open, a blockage of this sort arises, that the sacks become wedged together or even fall off the conveyor belt. Here too an attendant has to clear away these obstructions by employing muscle power. Furthermore, because of its many moving parts, a device of this kind is liable to breakdowns and has a high maintenance cost.
U.S. Pat. No. 3,596,842 discloses a similar device for the unpacking and separation of granulated substances packed in paper or similar material. The device consists of a funnel that conveys the packages to an isolating device, from which the packages fall as a result of gravity into the unpacking equipment. The unpacking equipment consists of several staggered rotating shafts on which toothed disks are arranged and whose rotational direction is determined. The packaging remnants and the unpacked granulate fall from the unpacking equipment onto a separation assembly arranged underneath. The separation assembly consists of an inclined electromechanically driven vibrating sieve, through which the granulate falls.
The invention therefore takes as its basis the task of specifying a bag opening and slitting device which, by technically simple means, constantly ensures a sure slitting open of the sacks (for example, coffee sacks), is easily handled, and is economical to manufacture.
This task is solved with a device of the kind mentioned at the beginning inventively by this, that in a housing at least one mechanically propelled shaft is arranged, on which in each case at least one cutting member is firmly mounted, and the housing has an inlet opening, through which the filled sacks can be brought either mechanically or by gravitational feed, and shows an outlet, through which the slit-open sacks and the goods released from the sacks can be led off by gravity, and that the housing has devices with which it can be attached to and detached from a transport container for sacks. Furthermore, the device comprises at least one moveable restraining apparatus fashioned in plate form with longitudinal slits, through which in a released state the at least one cutting member projects for optionally covering or releasing the at least one cutting member, wherein said restraining apparatus is movable by a drive assembly from a first position in which the restraining apparatus is in a covered state and prevents sacks from reaching the at least one cutting member to a second position in which the restraining apparatus is in a released state and allows sacks to reach the at least one cutting member.
By this restraining apparatus it is possible continually and directedly to convey the sacks to be cut to the cutting members.
By using at least two shafts, it is possible to slit open several sacks at the same time, so that the isolation of these sacks is omitted.
The number of sacks that can be slit open simultaneously can be increased by arranging three or four shafts next to each other, optionally allocated with regular distribution.
With this it is advantageous if, on each shaft, blades or disks are mounted with a regular or arbitrary distribution of the sort that the blades or disks of neighboring shafts are in a staggered arrangement. With this it is especially advantageous if the blades or disks have a rotation diameter that is greater than the distance of the shafts from each other. Especially for reasons of space, it can be advantageous to provide the blades or disks with different rotational diameters.
Although it is thoroughly conceivable according to the invention to arrange this device at the lower end of a slide or chute, which gravitationally conveys the emptied sacks to the device, it is especially advantageous so to fashion the invention-device on a housing can be fastened to and later detached from a transport container, which can be a truck with a bin attachment or a standard container for this, pins can be allocated at the four corners of the inlet opening, which engage with the latched openings present on the corners of the loading opening of the truck, container, or the standard container and can be made fast in them. In any case, for this a horizontal process of the device in the direction of the untitled container or standard container is necessary.
The attachment process can be made easier by having hooks on the upper two corners of the inlet opening, which can be hung in the upper two latched openings of the front side of the container or standard container, and by having pins on the lower two corners of the inlet opening, which engage the lower two latch openings and can be made fast with them.
For carrying out the process of slitting open, these transport containers or standard containers are tilted into an inclined state, for instance, by means of the tilting mechanism of the truck transporting the standard container.
In some cases it can occur that the sacks in the transport container can either be loaded wrongly or be thrown into disorder during transport and, in the process of tilting the transport container, form so-called sack-bridges, which prevent a further sliding of the sacks to the cutting apparatus. In a case of this sort, the inclination of the transport container must be sharply raised, so that the sack-bridge collapses. With this, however, the sacks can suddenly fall onto the blades or disks and brake these to a standstill. Also, the outflow of goods, for instance, coffee beans, and the cut open sacks is sometimes so disorderly that the equipment, which follows for the separation of sacks and goods, or for further processing, cannot process the intermittent accumulations of product.
Thexe2x80x94for examplexe2x80x94hydraulically operated restraining apparatus can take different processing positions for the exact measuring out of the cutting process and also can be regulated within these positions.
In order to ensure good operation with the minimal need for space of the restraining apparatus, it is advantageous that the rods or the plate(s) be so bent that, in the covered state of the restraining apparatus, the upper part of the rods or plate(s) extends over the rotation radius of the blades or the disks and the lower part of the rods or plates stands vertically and fully covers the conveyor opening(s) to the blades or disks.
In case the transport containers are loaded right up to their loading opening, it can occur that in the inclined state of this transport container, the once vertical state of the sacks, seen from the loading opening, is inclined almost as a compact wall, closed to the cutting apparatus, and through it no individual sacks can arrive at the blades. With this it is an advantage to arrange a horizontally running beam in the region of the inlet opening, which can also be located in the entrance opening or at the height of the lower shaft, in order to xe2x80x9cbreak upxe2x80x9d the wall of sacks.
This xe2x80x9cbreaking upxe2x80x9d can be improved by arranging a moveable cutting apparatus at the height of the beam, whichxe2x80x94for instance, by hydraulic operationxe2x80x94cuts open at least one of the sacks at the level of the beam.
So that the sacks cannot fall from above onto the blades or disks, it is advantageous to mount, in the inlet opening above the only or the uppermost shaft, an inclined deflector from the edge of the housing to the shaft.
The invention takes further as a basis the task of specifying a procedure for slitting open the sacks, for example, coffee sacks, which guarantees a simple, constantly secure, time-saving, and economical slitting open of the sacks.
According to the invention, this task is solved by this, that, at the loading opening of a transport container loaded with sacks, a device for the slitting of sacks is connected and subsequently the sacks are conveyed either mechanically or by gravity to this device.
In order to ensure the slitting of all sacks, a guiding assembly is recommended which is disposed opposite to the cutting edge of each cutting member of the lower shaft for feeding the sacks in the direction of the cutting member. It is favorable when the guiding assembly is formed as a plurality of narrow sheet metal elements which are bent in order to provide a guideway for the sacks. Each sheet metal element should correspond with a respective cutting edge of a cutting member.
The mechanical conveyance can be carried out advantageously by means of a sliding floor present in the transport container, while the desired or necessary gravitational effect is attainable by tilting the transport container, by which a truck carrying the transport container can even be driven onto a ramp or something similar. By this, for reasons already given, a restraining of the sacks by means of a restraining apparatus up to the desired or necessary inclination can be advantageous.
In operation a cutting device provided with a restraining apparatus is, for instance, mounted on a container or standard container to be emptied. The restraining apparatus is moved with hydraulics in the direction of the container and above all prevents the sacks from sliding into the cutting blades. Then the container is tilted to the desired or necessary angle. The sacks slide against the restraining apparatus, but not yet into the blades. Now the restraining apparatus is returnedxe2x80x94Controlled, for example, by hydraulics. By this the cutting blades are free and the sacks can be slit open. By the placement of the restraining apparatus, the speed of the cutting process and thereby of the product flow can be regulated. By the high slanting position of the container, it is guaranteed that the sacks form no bridges and fully slide into the cutting blades. Moreover, the cutting process admits of being interrupted at any time with the restraining apparatus.
With this it is possible to cut open the filled sacks at any unloading site whatever and to convey the pile, consisting of cut sacks and the goods released from the sacks, to further processing.
Further characteristics and advantages of the invention result from the following description of an implementation form and the diagrams, to which reference is made.